Airway & Respiratory

Can’t Oxygenate, Can’t Ventilate, Can’t Intubate?

Case 1

EMS was called for a patient who was hypoxic after undergoing a failed tracheostomy tube change at home. The patient, a 62-year-old female, had a Medtronic Shiley tube in place due to severe COPD and obstructive sleep apnea. The tracheostomy tube had been in place for one year. The patient was not on a ventilator, but was tracheostomy dependent. The patient underwent a routine tracheostomy tube change at home by a visiting physician. In this instance, the physician removed the patient’s Shiley tube but was unable to replace it with a new device. She became tachypnic and hypoxic after 20 to 30 minutes while attempts were made to change the tracheostomy tube. EMS was called.

Upon EMS arrival, the patient was hypoxic to 60% on room air (RA), tachypnic to 40 and tachycardic to 140. She was hypertensive with a blood pressure of 156/96 and agitated. The patient received bag valve mask (BVM) ventilation through the stoma site and, due to the patient’s remote location, helicopter EMS (HEMS) was called for definitive airway management prior to transportation given the patient’s instability.

On aircrew arrival, the patient’s oxygen saturation with BVM through the stoma had improved to 95%. She remained agitated and tachypnic. The patient received ketamine and fentanyl for procedural sedation. The patient had a 6-0 tube placed through the stoma via a tube introducer (commonly called a bougie) and was then placed on the transport ventilator. Her oxygen saturation remained in the 90s and end tidal CO2 (EtCO2) confirmed appropriate tube placement with an initial value of 70. After the patient was placed on the ventilator, EtCO2 improved to 44.

The patient was transported via HEMS to a hospital ED with ear, nose and throat (ENT) surgical coverage. The patient’s condition improved throughout transport and she was transferred to the emergency department in stable condition. ENT was consulted and the patient was taken to the operating room where she had the Shiley tube replaced. The patient was discharged home the next day in stable condition.

Case 2

9-1-1 was called by bystanders after a significant motor vehicle crash. The patient, a 27-year-old male with no known medical history, was the unrestrained driver in a car that struck a tree on a sharp turn at a high rate of speed. The patient was ejected from the vehicle through the windshield.

On EMS arrival, the patient was found on the ground next to the car. He was unresponsive with a Glasgow Coma Scale (GCS) of 4 (E1 V1 M2). The patient was noted to have extensive facial trauma with bright red blood from the mouth as well as active vomiting. The patient had decreased breath sounds on the left with evidence of abrasions to the left chest wall and abdominal distention. Initial vitals revealed a heart rate of 154, blood pressure of 80/40 and an oxygen saturation of 68% RA.

The patient initially received BVM ventilation, but had jaw instability preventing an adequate seal. He remained hypoxic. A King airway was placed, but with the copious blood and secretions, the patient was unable to be oxygenated or ventilated with the supraglottic device. Intubation was attempted, but anatomy could not be identified given the amount of blood in the posterior oropharynx, so an endotracheal tube was unable to be passed.

The patient remained hypoxic with agonal respirations. The decision was made to perform a cricothyroidotomy. The procedure was performed and tube placement was confirmed with continuous EtCO2 with a value of 22. The patient’s oxygen saturation improved to 96% with a fraction of inspired oxygen (FiO2) of 100%. The patient also received needle decompression of the left chest given the hypotension, hypoxia and decreased breath sounds. A humeral intraosseous (IO) was placed and the patient received intravenous fluids. The patient was transported to the nearest level I trauma center.

On arrival at the ED, the patient’s heart rate, blood pressure and oxygen saturation had improved. The patient was found to have a subdural hematoma, left hemopneumothorax and splenic laceration. He was taken to the operating room for neurosurgical and trauma surgery interventions, and was then admitted to the surgical intensive care unit. The patient was eventually discharged to a rehabilitation facility.

Discussion

These two cases illustrate the importance of the ability of EMS to manage patients who cannot be oxygenated or ventilated and require advanced airway intervention. Management of these rare cases can be life-saving, but the required interventions are rarely performed in practice. The following discussion will examine the anatomy of the larynx and steps for using an endotracheal tube introducer to aide in the securing of tracheostomy and cricothyroidotomy airways. The authors do not support any particular device or brand of equipment, nor does the following represent the views of the U.S. Air Force.

Anatomy

The neck contains airway as well as vascular, muscular and nervous system structures. The carotid arteries and jugular veins exist lateral to the midline of the anterior neck.1 Occasionally, branches of the superior thyroid artery, which originates from the external carotid artery, may be located in close proximity to the cricothyroid membrane. These structures should be avoided when performing any surgical airway procedures to prevent further blood loss. Trauma to these vessels can also lead to hematoma formation and distortion of airway anatomy.

There are various muscle groups of the neck that are divided based on location, above or below the hyoid bone.1 Suprahyoid muscles aid in swallowing. Lateral head movements are accomplished by the infrahyoid muscles such as the sternocleidomastoid and scalene muscles. The recurrent laryngeal nerve is a branch of the Vagus Nerve (CN X) and supplies some muscles of the larynx.1 Injury to the recurrent laryngeal nerves can result hoarseness or loss of voice.2

The hyoid bone sits superiorly to the thyroid cartilage and is at the level of the C3 vertabrae.1 The hyoepiglottic ligament connects the anterior surface of the epiglottis to the body of the hyoid bone. When a Macintosh blade is placed in the vallecula and moved anteriorly, pressure is placed on the hyoepiglottic ligament to pull the epiglottis anteriorly and expose the glottis.

larynx anatomy for endotracheal intubation

The thyroid cartilage sits just superior to the cricoid cartilage (See figure 1). The cricoid cartilage is located at level of the C6 vertebrae and is the only complete ring of cartilage around the trachea.1 The cricoid cartilage is attached to the thyroid cartilage anteriorly via the cricothyroid membrane and ligament. In adult cadavers, the size of the cricothyroid membrane varies from 8 to 19 mm (mean 13.69 mm) vertically, and from 9 to 19 mm (mean 12.38 mm) in the transverse direction.3 The cricothyroid membrane is bound by a cartilaginous cage, forming a lateral border to the cricothyroid membrane. The distance from the upper limit of the cricothyroid membrane to the vocal cord is 9.78 mm (+/- SE 0.52 mm).3 The tracheal rings sit inferior to the cricoid cartilage.

Cricothyroidotomy Overview

A cricothyroidotomy is a rarely performed but potentially life-saving procedure. Providers responsible for airway management must maintain familiarity with the necessary equipment and relevant anatomy. While debate continues regarding the best method among various techniques for performing the procedure, providers should be familiar with multiple approaches. This discussion will primarily focus on one particular surgical technique, but other approaches will be briefly discussed.

Needle cricothyroidotomy involves passing an over-the-needle catheter through the cricothyroid membrane.4 This procedure provides a temporary secure airway to oxygenate and ventilate a patient in severe respiratory distress where other means of airway management are not possible.

Needle cricothyroidotomy may be performed on patients of any age, but is considered to be preferable to surgical cricothyroidotomy in infants and children up to 10–12 years of age because it is anatomically easier to perform with less potential damage to the larynx and surrounding structures.4 The superior aspect of the pediatric trachea is not well developed in children, and surgical incisions through the cricothyroid membrane are associated with a higher incidence of subglottic stenosis. The exact age recommendations are institution dependent.

Some commercially available kits utilize the Seldinger technique to place an airway device through the cricothyroid membrane. This technique lessens the incision size needed and is more familiar to some providers who perform Seldinger procedures.5

The remainder of this article will focus on the bougie- assisted surgical cricothyroidotomy technique. Potential variations in technique will also be mentioned. This technique can be used to obtain a surgical airway as was needed in case 2, or a modified technique utilizing the endotracheal tube introducer can be used in a patient who loses a surgical airway already in place as was seen in case 1.

Cricothyroidotomy Indications

  • Failure to oxygenate
  • Failure to ventilate
  • Inability to otherwise manage the airway

Cricothyroidotomy Contraindications

  • Ability to secure an airway with less invasive means
  • Age
  •     Children <10–12 years of age
  • Airway trauma that involves the cricothyroid membrane or transection
  •     In this instance, a tracheostomy may be required

Cricothyroidotomy Equipment

Agencies and providers may vary slightly in the equipment stocked and used for the bougie-assisted surgical cricothyroidotomy procedure. The following is an example of equipment that can be used.

  • 6-0 endotracheal tube
  • 10 cc syringe to inflate endotracheal tube cuff
  • Scalpel
  • Endotracheal tube introducer (bougie)
  • Tracheal hook, forceps and retractors
  • Device to secure endotracheal tube
  • Skin sterilization solution
  • Sterile towel

Cricothyroidotomy Pre-Procedure Considerations

Time permitting, the surgical field should be cleaned, prepared and covered with some type of drape or sterile towel. Some emergency situations may not allow for this. Providers should always utilize personal protective equipment and be careful to avoid injury and exposure while performing the procedure. Pre-procedure sedation may be considered, but given the emergent nature of this procedure, sedation may not be able to be performed given concern for worsening respiratory status or hypoxia.

Positioning the patient appropriately will increase accessibility to airway anatomy. When possible and when required, cervical spine immobilization should be maintained, however, securing an airway in a patient who cannot oxygenate or ventilate, takes priority over cervical spine stabilization.

When possible, place the patient’s head in extension in the supine position. In adults, the prominence at the upper border of the thyroid cartilage can be palpated. The thyroid cartilage can then be followed inferiorly to locate the cricothyroid membrane.4 Palpating inferiorly from the thyroid cartilage, a grove can be felt; this is the location of the cricothyroid membrane.

If the cricothyroid membrane cannot be palpated, the “laryngeal handshake” may be utilized. This procedure involves the thumb on one side of the airway and the other four fingers on the other side. The provider starts superiorly and moves inferiorly, palpating the hyoid, thyroid and cricoid cartilages.6 It is important to remember that the cricothyroidotomy is a tactile procedure; the provider should maintain contact with the cricothyroid membrane (and resultant hole made after incision) continuously throughout the procedure.

Bougie-Assisted Surgical Cricothyroidotomy Procedure

Once the anatomy has been identified, stabilize the thyroid cartilage with the non-dominant hand while the dominant hand holds the scalpel.7 The type of scalpel used is provider and institution dependent.

endotracheal intubation

Figure 2

Make a vertical or horizontal incision over the cricothyroid membrane. A midline vertical incision is typically recommended to avoid vascular or nerve damage, however, a horizontal incision can be considered with easily palpable anatomy. The length of the incision will depend on the identification of the anatomy but should be at least large enough to pass a 6-0 endotracheal tube. (See figure 2.)

endotracheal intubation

Figure 3

Once the skin is incised, palpate the cricothyroid membrane position and bluntly dissect with fingers (or forceps) through subcutaneous tissue until the membrane is readily identifiable. Retractors can be used to aide in visualization. (See figure 3.)

endotracheal intubation

Figure 4

An incision should then be made through the cricothyroid membrane. Alternately, forceps can also be used to puncture the membrane. Lateral margins will be felt due to the cartilaginous cage. (See figure 4.)

Dilate through the incision with a gloved finger and palpate the tracheal lumen. Trach hooks can be utilized to help keep the incision site patent, if so desired. The posterior aspect of the cricoid ring may also be palpated while dilating the incision.

endotracheal intubation

Figure 5

Pass the endotracheal tube introducer (bougie) alongside the finger into the trachea or through the patent site held open by the trach hooks. (See figure 5.)

Confirm bougie position with finger, ensuring it passes through membrane.

The bougie will typically meet moderate resistance at the carina (around 10cm from the skin). The tracheal rings may also be felt with the passage of the bougie. The bougie should not be advanced further forcefully, as this could lead to airway perforation.

Pass the 6-0 endotracheal tube over the bougie. The tube may need to be twisted as it passes through the skin. The tube may be preloaded prior to bougie placement.

endotracheal intubation

Figure 6

Only advance the endotracheal tube until the balloon is in the airway and no longer visible, as further advancement can lead to mainstem intubation. (See figure 6.)

Inflate the endotracheal tube balloon.

Confirm endotracheal tube placement according to protocol. Recommendations include continuous EtCO2 measurement and auscultation for bilateral breath sounds.

Secure the endotracheal tube. Some providers may choose to cut the tube to lessen the length. This also cuts the balloon inflation port rendering this useless.

Tracheostomy Considerations

EMS personnel may encounter patients who have had a previous tracheostomy tube placed. A tracheostomy is located inferior to the cricoid cartilage, and patients may have a variety of cuffed and uncuffed tubes through the stoma site.

A modified technique similar to the above described procedure can be used for patients who lose a surgical airway and are unable to be oxygenated and ventilated. A bougie can be placed through the stoma site and the patient can then have a 6-0 endotracheal tube placed through the site as was described above.

The timing of the first tube change after tracheostomy tube placement is institution dependent and is also dependent on other factors such as delayed wound healing (patients taking steroids, patients with poorly controlled diabetes, and patients with nutritional deficits). After initial tracheostomy placement, wound healing is required so that the stoma is mature before the tube is changed. The initial tube change usually occurs in the hospital around post-operative day five, though patients who have a technically challenging placement may be taken back to the operating room for the first exchange.8,9 Subsequent periodic tube changes occur to prevent granulation tissue formation that could require the patient to have further surgeries for tissue removal.10 For outpatients with mature stomas, tracheostomy tube changes typically occur every 8–12 weeks.11

Generally, the stoma begins to mature at 5–7 days, but the site may not be completely mature. Dislodgement of the tracheostomy tube and attempted replacement may lead to a false tract. However, in emergency prehospital situations, attempted replacement may be required. The bougie in this instance would be particularly helpful, given its smaller diameter and greater ease in confirming placement in the trachea prior to placing a new tube.12

Conclusion

The cricothyroidotomy procedure is a rare but important procedure for all emergency providers. We present a particular technique that can be used for patients who require emergent cricothyroidotomy or in patients who lose an already established surgical airway. Emergency services personnel should be familiar with and able to perform multiple techniques and should have an understanding of the anatomy of the larynx as well as ways to optimize landmark recognition.

References

1. Netter FH. Atlas of Human Anatomy. 6 Ed. Feb. 14, 2014. Elsevier Health Sciences.

2. The New York Times Health Guide (n.d.) Laryngeal Nerve Damage. Retrieved on May, 25, 2016, from http://www.nytimes.com/health/guides/disease/laryngeal-nerve-damage/overview.html.

3. Bennett JD, Guha SC, Sankar AB. Cricothyrotomy: the anatomical basis. J R Coll Surg Edinb. 1996 Feb;41(1):57-60.

4. Mittal M. (Oct. 12, 2015) Needle cricothyroidotomy with percutaneous transtracheal ventilation. Up to Date. Retrieved on May 25, 2016, from http://www.uptodate.com/contents/needle-cricothyroidotomy-with-percutaneous-transtracheal-ventilation.

5. Jenvrin J, Pean D. Cricothyroidotomy. N Engl J Med. 2008 Sept 4; 359:1073-1074.

6. Chow Y. (Nov. 17, 2013) Levitan, the “Laryngeal Handshake” and the “Cartilaginous Cage.” PHARM: Prehospital and Retrieval Medicine. Retrieved on May 25, 2016, from https://prehospitalmed.com/2013/11/17/levitan-the-laryngeal-handshake-and-the-cartilaginous-cage.

7. Life in the fast lane (Apr. 4, 2016) Surgical Cricothyroidotomy. Retrieved on May 25, 2016, from http://lifeinthefastlane.com/ccc/surgical-cricothyroidotomy.

8. Tabaee A, Lando T, Rickert S, et. al. Practice patterns, safety, and rationale for tracheostomy tube changes: a survey of otolaryngology training programs. Laryngoscope. 2007 Apr. 117(4):573-6.

9. Fisher DF, Kondili D, Williams J, et. al. Tracheostomy tube change before day 7 is associated with earlier use of speaking valve and earlier oral intake. Respir Care. 2013 Feb. 58(2):257-63.

10. Yaremchuk K. Regular tracheostomy tube changes to prevent formation of granulation tissue. Laryngoscope. 2003 Jan. 113(1):1-10.

11. Lewarski JS. Long-term care of the patient with a tracheostomy. Respir Care. 2005 Apr. 50(4):534-7.

12. First 10 EM. (n.d.) Respiratory Distress in a Patient with a Tracheostomy. Retrieved May 25, 2016, from https://first10em.com/2015/05/26/respiratory-distress-in-the-patient-with-a-tracheostomy.

 

Authors:

Powell MD, Elizabeth K. Capt

Galvagno DO, PhD, FCCM Samuel M. Lt Col

Lucero BSN, RN, CFRN, Joel Maj

Simoncavage RRT, Matthew TSgt

Koroll, Nathan TSgt

O’Neal, Preston SSgt

Bystry, Marja SrA

Castaneda, Jathen SrA

The 943rd Critical Care Air Transport Team (CCATT) is a part of the 943rd AMDS; 943rd Rescue Group, Davis-Monthan Air Force Base, Arizona. The article represents the opinion of the authors and does not constitute an endorsement of any particular product. Any views expressed are those of the authors and not the United States Air Force. Questions can be directed to the corresponding author Dr. Powell at [email protected]